A weekly and surely fictitious account of events in a naval detachment only loosely connected with the Senior Service.

Set on board the British Royal Navy frigate HMS Troutbridge, the show follows the adventures of Sub-Lieutenant Phillips, scheming Chief Petty Officer Pertwee, and bemused Lieutenant Murray. The trio often have to cover up problems and mistakes from the ship’s commander, “Thunderguts” Povey.

Episodes were self-contained, although there was continuity within the series, and sometimes a reference to a previous episode might be made. A normal episode consisted of Sub Lt Phillips, scheming Chief Petty Officer Pertwee, and bemused Lt. Murray trying to get out of trouble they created for themselves without their direct superior, Commander (later Captain) “Thunderguts” Povey finding out. Scenes frequently featured a string of eccentric characters, often played by Ronnie Barker or Jon Pertwee. Over the course of the programme Lt Murray marries Admiral Ffont-Bittocks daughter Rita.

The Republic of Potarneyland, a country situated somewhere on the Indian subcontinent, is featured in several episodes. Over the course of the series, it is revealed that Potarneyland had recently been granted independence from Great Britain, and had joined NATO because the Potanis considered it to be a “free gift scheme”. During Series 3 of The Navy Lark, a Potarneyland frigate, the Poppadom, appears in several episodes manned by various Potani officers voiced by Michael Bates and Ronnie Barker.